Genetic HL w/ External Ear Abnormalities & Eye Abnormalities Flashcards
what is mandibulofacial dysostosis
treacher collins syndrome
what is the heredity of treacher collins syndrome
AD w/ almost 100% penetrance
majority are deletions or nonsense mutations
60% of cases are new mutations with the father tending to be older
is treacher collins syndrome a 1 & 2 branchial arch syndrome
yes
what is a deletion mutation
codon is incorrectly read
what is nonsense mutations
stop codon instead of another codon
how do you read 5q31.3
chrom 5, long arm q, region 33, band 3
what is a teratogenic
any agent that causes an abnormality following fetal exposure during pregnancy
only causes a mutation in a developing embryo or fetus in the environment
clinical features of treacher collins is characterized by
abnormalities of facial structures formed form first pharyngeal arch
coloboma, fish mouth
FIRST PHARYNGEAL ARCH SYNDROME
treacher collins syndrome
what is atresia
small ear canal
what are audiologic findings of treacher collins
malformed pinna and EAC atresia, absent or malformed ossicles
mild to moderate bilateral conductive HL in >50% of cases
can you fix treacher collins with a baha?
yes
what is the differential diagnosis of treaacher collins
oculo-auriculo-vertebral spectrum (OAV) disorder
when facial structures are not put together normally and they look off
dysostosis
what is BOR
Affects structures developing from branchial arches, ears, & kidneys
branchio oto renal syndrome
second most common cause of AD HL
BOR
associated with a transcription factor involved in development of the inner ear and certain kidney cells
BOR
what is Mondini’s malformation
cochlea doesn’t complete the full turns
have severe-profound snhl
what are characteristic findings of BOR
AD transmission with variable expressivity
renal abnormalities with varying severity
unilateral/bilateral preauricular pits
external ear anomalies
HL (conductive, mixed, or snhl
what is BOR differential diagnosis
alport’s
what is a characteristic of chromosomal disorder?
have many different systems involved
multifactorial inheritance pattern:
affects many genes and environmental factors
complex is a predominantly unilateral malformation of craniofacial structures developing from 1st & 2nd branchial arches
OAV
What is OAV
complex of 3 rare congenital disorders believed to be related to one another
range of severity affecting eyes, ears and vertebral system
what are the 3 rare congenital disorders related to one another
goldenhar syndrome
hemifacial microsomia
OAV
goldenhar syndrome
hemifacial microsomia
OAV
which is the most severe? which is the midlest?
golden har is severe
oav is mildest
What is different about OAV and treacher collins?
OAV more unilateral and treacher collins doesn’t have the skeletal abnormalities or vision problem but this one does
clinical features of OAV
asymmetry** vision loss, skeletal issues, conductive hearing loss, pinna abnormalities
what does CHARGE stand for
coloboma
heart defects
atresia
retarded development
genital abnormalities (hypogonadism)
ear anomalies/deafness
what is hypogonadism
underdeveloped sexual organs
clinically infertile
does someone have to be blind and deaf to be called deafblind syndrome?
do not have to be completely deaf or completely blind, just if both systems are affected in any severity is it considered this
no matter the severity if you have issues with both systems it is considered this
what is an example of deafblind syndrome
down syndrome
ushers
CHARGE
what are clinical features of CHARGE
snhl and progressive
external ear anomolies
deaf blind syndrome
increased risk if father is older
could be misdiagnosed as autism because of sensory deprivation
charge
what type of HL is seen in charge?
majority is SNHL
most common AR syndromic HL
usher syndrome
what are the most common symptoms of usher syndrome
progressive HL and blindness associated with retinitis pigmentosa (develops around 2nd decade)
what is retinitis pigmentosa
scarring of the retinal pigment layer with uneven gather of pigment nito clusters
initially periphery is affected then progresses to the center
describe the vision loss seen in ushers
difficulty seeing at night in teen years
progressing to tunnel vision
progressing to blindness by 30-40
Most common types of ushers in us
type I and II
describe the 3 types of ushers
type I is the most severe - congenital severe to profound snhl
type II : hearing is affected with milder HL, vestib is unaffected
type III: very rare, has progressive vestibular dysfunction
what is the differential diagnosis for ushers
norrie syndrome
is the deaf community accepting of CI’s in ushers syndrome
yes
what is neuropathy
dysfunction of the nerves, pain, tingling and auditory neuropathy
what is auditory neuropathy
lack of understanding of speech
what are other syndromes associated with RP and SNHL
Hallgren, Cockayne, Alstrum, & Refsum syndrome
Hallgren, Cockayne, Alstrum, & Refsum syndrome all
all autosomal recessie, hl is snhl progressive, all progress to blindness, intellectual disability is common
what are the symtpoms of norrie syndrome
visual problems, SNHL and dementia, and intellectual disability
what is the inheritance of norrie syndrome
x linked recessive
x linked from mom
M & F have 50% chance of having it from mom and only boys will manifest it
x linked from dad
only girls get it and they will not manifest the phenotype (carriers)
Norrie is a ____ phenotype
male, females will be carriers (x linked recessive)
the most common cause of congenital retinal detachment
norrie syndrome
differential diagnosis of norrie syndrome
usher
CMV infection
rubella
differences between ushers and Norrie
Ushers is due to RP and norries is not
